Hi,

Does anyone have the JF Automotive transmission flash done?

I can't find any reviews and wanted some feedback from those who have. Is there any real improvement in acceleration, launching and transmission response? Or is it all smoke and mirrors?

Cheers

 

Try posting up over on the F forum. There is a guy over there who has a done a TCU flash along with 100 other mods...

 

Until this very minute I was only aware of one only transmission tune that was done on a Jaguar, and that was a forum member in the US who had a transmission tune done by some mysterious ex-Bosch engineer from the UK in partnership with a US-based tuning company.

Never heard of JF Automotive until today...

 

Pardon my ignorance, I'm new here. What is the French forums? I just thought posting here would be the most relevant to my model.

What does the F forum cover? Feed types only? Same transmission as XFRs?

 

I guess I'll be a guinea pig. It's not that expensive

 

Humm...interesting...what is the cost?

 

"Gearbox Tune would give you 10-15% Faster Gearshifts, Lock the torque converter up sooner in the rev range, Quicker paddle response and smoother all round gearshifts.
JFA Gearbox Tune £275.00 +Shipping


The gearbox tune will come with a tool that you simply plug straight into the OBD port and it will automatically load the file to the car. "

 

ZF transmissions are not cheap so ya might want to do some research before loading a canned trans tune into yours? Honestly if there tune is all that, info on it should be readily available since our trans is shared with so many OTHER manufacturers like BMW.

 

If you're gonna do this, I wanna see it being done, so let me know if/when and I'll be there!

 

I think I might know just a touch more on these transmissions than you (may think I know). Specifically this line of 6HP ones. The one in the XFR is known as a 6HP26. It's used in many cars as you stated. These are also used in Ford Falcons in Australia, with a company called Nizpro who have built 6HP26s to handle well in excess of 1000nm, ad most of us should know it's torque that kills transmissions, not horsepower.

In regards to your statement about information being readily available since the transmission is shared with so many, this part is incorrect. ZF ships these transmissions out to manufactures with a base calibration. Each manufacturer then applies their own encrypted tunes on each. Each company's level of encryption also varies, from easily unlocked to virtually impossible.

My other car is a heavily modified 335i which runs one of the weaker variations of the 6HP, the 6HP21. Nizpro and a couple of other companies in other parts of the world have been trying to crack the BMW encryption for years. The code can be read but it's about 1800 tables that aren't indexed. There has finally been some progress, thanks to their experience with the Ford transmissions they hado developed years ago. It was a much simpler process.

I had a 2 hour tour of the facility and discussions with the company director and he went through the BMW transmission developments that I have on order, including re-engineered baskets and clutches, but without the software, the hardware was only half the hurdle done.

Damn, I've gotten so off topic lol anyways, basic software calibration isn't going to damage the 6HP26. It can handle a great deal of torque before needing hardware upgrades.

This TCU flash that I available might just be smoke and mirrors with no benefits. It might not be. I'm well aware of the risks, but realistically, the only real risk here would be bricking the TCU.

Ithe would be a pricy experiment if it goes wrong, but I'm willing to take that risk if it may benefit others in wanting to do the same but hesitant.

Pioneers get the arrows, settlers get the land.

P.S. Sorry for the long post. I ramble quite a bit.

P.P.S. Will this is by no means meant to be taken as an aggressive response to your post. I think more discussion and trial and error will benefit the community.

I'm also aware the crowds who own these cars are far different to the BMW N54 community I come from, with far less people willing to alter the way their cars came from the factory, also since they are relatively newer and the entry costs are far higher than the BMWs that so many kids are modifying

 

I didn't see this message! Ignore my questions regarding this in my reply to your PM. I will order it and bring it to Sydney next time I'm down and we can do this together and see it there is an improvement!

I will be purchasing a VBOX so we can make quantifiable comparisons between the two in acceleration times instead of seat of the pants feeling!

 

LoL, I've never spoke to an "engineer" about transmissions at any length, but I have had a hand in rebuilding a few, and I have been witness to what a canned tune can do to an engine and trans at the track, and on the dyno. And yes we Jag fellas may be a bit cautious to un proven mods, but a wise man learns from a fools mistakes, so I'll gladly defer the role of teacher to you. Happy modding!

 

I'm willing to be the "fool" for the sake of others and am well aware of the possible risks. But how do you expect unproven mods to become proven? Without risk, there is no progress. The more you stay still, the faster the world moves around you.

If everyone was so negative to people testing new things, nothing would change. Many Jaguar owners complain that there is so little aftermarket support for their cars. If everyone was encouraging enough, maybe more stuff would get developed, boundaries pushed, enough people failing and stumbling to work out what works and doesn't work so the greater community can benefit.

It doesn't hurt to be a little selfless sometimes.

 

Just to play devils advocate here, pretty sure the trans in our cars is the 6HP28.

 

Haha I don't know much at all!! Glad to admit when I'm wrong!

 

I only know because I rebuilt the valvebody with a Sonnax Zip kit (highly recommended!)

 

Cool! I was thinking of fitting one to my 6HP19. What kind of improvements did you see? Did it tighten up the shifting?

 

Some good news, my Racelogic VBOX Sport arrived. The TCU flash hasn't though. I bought the VBOX to get quantitative data instead of just seat of the pants feeling measurements.

I plan on doing standing start acceleration tests and rolling acceleration tests, 0-100 km/have and say 60km/h to 200km/h. Not on public roads, of course.

Maybe three to five runs of each stock, then runs with the TCU flashed. I will do a standing start measurement, then a rolling measurement. Then repeat a few more times. Runs will be done in the same section of the track each time, as close together as possible to get consistent a temperature, on a full tank of petrol. I'll bring a Jerry can to fill up after the stock runs before flashing.

10 runs might be a bit hard with time constraints, 3 stock and 3 flashed should be possible.

What does everyone think? Any other measurements I should make? Different process or different speeds?

I'd like to measure the shift times but I think that might be virtually impossible without a much more expensive data logging setup.

 

Is there a reason why you couldn't use a digital sound recorder, put it onto the computer then play it back really slowly and mark the change in tone corresponding to the gear change? I know it's very low tech - but...

 

That's a pretty good idea! I could record it but my pea brain wouldn't know how to do the rest.

If someone would volunteer to do that, I'd happily record it.

They claim 15% faster shift times and claim that a couple of their customers had improved their quarter mile times. To be honest, I really don't know how they can back up this claim and I'm dubious there will be any real world improvement, but I'm willing to give it a try out of curiosity.